Stereoselective Cross-Coupling Reaction of 1,1-Diboryl-1-alkenes with Electrophiles:  A Highly Stereocontrolled Approach to 1,1,2-Triaryl-1-alkenes

Abstract

Palladium-catalyzed cross-coupling reaction of 1,1-diboryl-1-alkenes with aryl and alkenyl iodides was found to proceed stereoselectively, giving rise to the corresponding mono-coupled product as a single diastereomer with E-configuration. Second coupling of the initial product with another aryl iodide affords diverse triarylalkenes in their stereochemically pure form. This highly stereoselective approach for triarylalkenes allows one to synthesize both diastereomers in one pot from 1,1-diboryl-1-alkenes.

Oligomeric and Polymeric Systems with a Cross-conjugated π-Framework

“…[35][36][37][38][39][40][41] Of particular note are the allene analogues 32-34, which were reported by Hopf and Lehrich (Scheme 10). 42 More recently, cross-conjugated allenes 35 and 36 have been reported by Diederich and co-workers, 43 as well as a large series of tetraethynylbutatrienes 37.…”

Transition metals in organic synthesis: Highlights for the year 2005

“…Stereoselective coupling of 1,1-diboryl-1-alkenes with aryl iodides was reported (Eq. (9)) [150]. A variety of heteroaryl boronic acid derivatives were used such as, haloimidazolyl [151], 2-and 3-thiophenyl [152] in a synthesis of rebeccamycin analogs [153], 3-pyridyl [154], 5-pyrimidyl [155], 1,4,5,6-tetrahydropyridyl [156], 2-indolyl [157] and 3-furyl [158].…”

Haloboration of Internal Alkynes with Boronium and Borenium Cations as a Route to Tetrasubstituted Alkenes

“…[1,2] Although alkyne hydroboration is a powerful synthetic route, [3,4] it is not applicable to the synthesis of trisubstituted vinyl boronates. Thus, alternative regio-and stereospecific methods are needed, particularly for subsequent use in the formation of tetrasubstituted alkenes, [5][6][7] as the production of these important biologically active compounds as single isomers by classical methods is challenging. [8] One simple approach to trisubstituted vinyl boronates is the functionalization of internal alkynes by metal-catalyzed 1,2-carboboration [9][10][11][12][13] and 1,1-carboboration.…”